Frost dates for 08525Hopewell, NJ
The average last spring frost in Hopewell is April 16 and the average first fall frost is October 27, giving a typical growing season of about 192 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 16
- Average first fall frost
- Oct 27
- Growing season
- 192 days
Safer after May 1 (1-in-10 risk)
Possible by Oct 10 (1-in-10 risk)
Last frost typically in 164 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 15 · Apr 30 · May 15 | Oct 1 · Oct 14 · Oct 30 | 167 days | 100% |
| Frost / freeze (32°F) | Apr 3 · Apr 16 · May 1 | Oct 10 · Oct 27 · Nov 9 | 192 days | 100% |
| Hard freeze (28°F) | Mar 20 · Apr 3 · Apr 16 | Oct 25 · Nov 7 · Nov 23 | 217 days | 100% |
Planting calendar for Hopewell
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 16 – May 22 |
| Tomatoes | Transplant outdoors | May 2 – Jul 7 |
| Peppers | Start seeds indoors | Mar 16 – Apr 16 |
| Peppers | Transplant outdoors | May 16 – Jun 16 |
| Eggplant | Start seeds indoors | Apr 2 – May 1 |
| Eggplant | Transplant outdoors | May 16 – Jun 16 |
| Cucumbers | Sow outdoors | May 16 – Jul 17 |
| Summer squash | Sow outdoors | May 2 – Jun 16 |
| Winter squash & pumpkins | Sow outdoors | May 16 – Jun 16 |
| Snap beans | Sow outdoors | May 2 – Aug 9 |
| Sweet corn | Sow outdoors | May 2 – Jul 7 |
| Watermelon & cantaloupe | Sow outdoors | May 16 – Jun 16 |
| Okra | Sow outdoors | May 9 – Jun 1 |
| Peas | Sow outdoors (spring) | Mar 16 – May 1 |
| Potatoes | Plant outdoors (spring) | Mar 16 – May 16 |
| Onions | Start seeds indoors (spring) | Feb 2 – Mar 1 |
| Onions | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (spring) | Feb 26 – Apr 1 |
| Broccoli | Transplant outdoors (spring) | Apr 2 – May 1 |
| Broccoli | Start seeds indoors (fall) | Jun 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 16 – Mar 16 |
| Cabbage | Transplant outdoors (spring) | Mar 16 – Apr 16 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 16 – Jun 1 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 9 – Apr 22 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 16 – May 6 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Apr 2 – Apr 22 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 16 – Jun 1 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 08525 is matched to the NOAA station Wertsville 4 Ne, NJ, 6.9 km away, at 283 ft elevation (53 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Wertsville 4 Ne, NJ (used) | 283 ft | Apr 16 | Oct 27 |
| Trenton Mercer Co Ap, NJ | 184 ft | Apr 10 | Nov 1 |
| Trenton State College, NJ | 100 ft | Apr 17 | Oct 28 |
| Lambertville, NJ | 68 ft | Apr 16 | Oct 19 |
Frost dates near Hopewell
- Blawenburg, NJ 08504 · last Apr 16, first Oct 27
- Pennington, NJ 08534 · last Apr 10, first Nov 1
- Skillman, NJ 08558 · last Apr 16, first Oct 27
- Ringoes, NJ 08551 · last Apr 16, first Oct 27
- Princeton, NJ 08542 · last Apr 10, first Nov 1
- Rocky Hill, NJ 08553 · last Apr 25, first Oct 16
- Belle Mead, NJ 08502 · last Apr 16, first Oct 27
- Titusville, NJ 08560 · last Apr 10, first Nov 1
Frequently asked questions
- When is the last frost in Hopewell, NJ?
- For ZIP code 08525, the average last spring frost (32°F) is April 16, based on NOAA 1991-2020 climate normals for the Wertsville 4 Ne, NJ weather station. There is a 1-in-10 chance of a frost after May 1.
- When is the first frost in Hopewell, NJ?
- The average first fall frost (32°F) is October 27. There is a 1-in-10 chance of frost by October 10, so tender plants are at risk from that point on.
- How long is the growing season in 08525?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 192 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.